Interview with Pam Matson

Interviewer: Tell me about what you do and how you came to be interested
in this project.

PAM: I’m a professor in geological and environmental
sciences at Stanford University and I’m a biogeochemist by training.
I study the chemical interactions between plants and microorganisms and soil
and water and atmosphere systems, and I focus, in particular, on nitrogen.
A lot of my research is focused on what happens with nitrogen fertilizers
in agricultural systems and how they affect the environment.

Interviewer: Would you describe the nitrogen cycle in layman’s
terms for us.

PAM: The biogeochemical cycle of nitrogen is one of the
grand element cycles of the planet. All organisms need a lot of nitrogen:
plants and people and all different kinds of animals and microorganisms use
nitrogen in our cells. We use it in proteins and amino acids; plants use nitrogen
in chlorophyll, the machinery of photosynthesis. We need a lot of it and,
of course, we’re literally bathed in it. The atmosphere is 78% di-nitrogen
(two molecules of nitrogen connected together making it very, very hard to
break down) so there should be plenty. But the problem is that most organisms
don’t have access to that di-nitrogen in the atmosphere. They can’t
use it. They can’t get at it. But there is a group of microorganisms
called nitrogen-fixing bacteria that have the ability to break apart the di-nitrogen
that’s in the atmosphere into parts that they can use in their own biomass.
Then when they die and decompose, the rest of the organisms on the planet
get access to that nitrogen. Once that nitrogen’s in plants and in soil,
we use it in our cells, microorganisms use it to grow, and some of it gets
stored in soils in different forms, in organic forms and in inorganic forms
that can be easily lost in water or to the atmosphere. When microorganisms
use nitrogen, some of them release di-nitrogen back into the atmosphere. And
so that completes the cycle. We have di-nitrogen in through the microorganisms,
all other organisms use it, it’s stored in soils and water systems,
and ultimately bacteria de-nitrify it back out to the atmosphere. That’s
the natural nitrogen cycle.

That’s how the world worked until about 50 years ago when people started
fixing nitrogen out of the atmosphere using energy provided by fossil fuels,
by oil and gas. We use the energy from fossil fuels to break apart di-nitrogen
and make it into fertilizer nitrogen like ammonia fertilizer, nitrate, urea
fertilizers that we use to grow plants and agricultural crops. We also started
purposefully growing a lot of nitrogen-fixing crops like soybeans and peas
and beans. Those two activities – making the fertilizer and growing
nitrogen-fixing crops – have together added a huge amount of nitrogen
into available forms around the planet. We’ve actually more than doubled
the amount of nitrogen that now becomes available every year for all these
plants and animals to use. And that’s a huge change in the global cycle
of nitrogen.

The consequences of all that extra nitrogen are some good and some bad. The
good ones are of course that it allows us to grow more food. We need to add
fertilizer nitrogen to maximize the yields of a lot of different crop plants.
By yields I mean the amount of food that’s produced per unit area of
land surface. Fertilizer nitrogen has been very important in the successful
increase of food production over the last 30 or 40 years. But one of the problems
with all that extra nitrogen going into land in the fertilizer is that it
doesn’t all get used by plants. In fact, maybe on average, 50% of the
nitrogen doesn’t stay in agricultural systems but rather gets transported
out of agricultural systems and goes off to the atmosphere in a number of
different forms, including nitrous oxide, which is a greenhouse gas, nitric
oxide, which is an air pollutant. Also some of it goes off as di-nitrogen,
that di-nitrogen that the atmosphere is filled with and that has no environmental
consequences. Some of the nitrogen in agricultural fields just leaches out
through the soils into groundwater systems, or runs off the surface into surface-water
systems like streams and rivers and lakes. And there it causes a number of
different problems.

It can cause acidification of the lakes in some cases, and can cause disease
in humans if there’s enough nitrate in the water that we drink. But
probably the biggest problem for nitrogen is that it moves off of the land,
through the rivers, down into the coastal waters of the continents. And in
the coastal marine waters, a lot of extra nitrogen can cause huge blooms of
algae, of phytoplankton in the oceans. Those huge blooms ultimately result
in the phytoplankton dying off, sinking down, and being decomposed. And when
that happens, sometimes the waters are driven to very, very low oxygen levels
-- they’re anoxic waters -- and that kills fish, kills shellfish, drives
fish away, and causes lots of harm to the coastal marine environments. It
also causes a lot of economic losses to the fisher people who use those resources.
So there’s a lot of inadvertent negative consequences of fertilization.
One of the big challenges that we’re trying to address is how you can
use fertilizer to grow food and meet the needs of people for food, but at
the same time do it in a way that has less negative consequence for the environment
that we use.

Interviewer: Why is it that in the coastal waters the phytoplankton,
single-cell organisms, are always there even when the nitrogen-rich water
washes comes off the crop land and washes into the river systems?

PAM: Coastal waters off of the continents tend to be relatively
rich waters. There are lots of organisms that live there, lots of phytoplankton,
which are single-celled plants basically, that have the ability to fix or
to carry out photosynthesis, and lots of animals as well. But the phytoplankton
are especially influenced by nutrients coming off of land, nutrients like
nitrogen that come off of land into the river systems. Their growth tends
to be limited by the amount of nitrogen that’s there. If you add extra
nitrogen, they respond by growing very, very well and that leads to huge blooms
of the phytoplankton. That’s not necessarily a good thing for those
ecosystems because those phytoplankton die eventually and sink down low into
the ocean water column. and as it sinks down, the phytoplankton gets decomposed
by bacteria and other kinds of microorganisms in the water column. And in
decomposing those phytoplankton cells, they take a lot of oxygen out of the
water, leaving the water to become very, very low in oxygen. That’s
called anoxic. That, of course, kills off animals that are there that can’t
move, like the shellfish, and drives away any other animals that can swim
away. So you run into areas that are called dead zones where there’s
very little life left in those systems, at least life in terms of fisheries.
That has tremendous impact on the fishermen and women who make their livelihoods
on fishing in the coastal waters, and it also has really negative consequences,
of course, on the biodiversity and the health of the coastal ecosystems.

Interviewer: About 50 years ago, the Haber process started creating
a more abundant supply of nitrogen. What has happened to all that nitrogen
and how does that influence the nitrogen process?

PAM: The Haber process that you mention is a process by
which we use energy from gas and oil to break apart the di-nitrogen in the
atmosphere and make it into fertilizer forms like ammonia or nitrate or urea.
Since we learned how to do that process and started creating and making fertilizer
nitrogen, we’ve added as much nitrogen through our human-made process
as happens naturally in the global system. Some of that excess nitrogen goes
off to the atmosphere in the form of an air pollutant and a greenhouse gas
form; some of it goes back to di-nitrogen, which we already have a lot of
in the atmosphere. Some of it goes into water systems where it leads to pollution
of various sorts. The big issue for us is how to manage that nitrogen fertilizer
better, so that we can still increase plant growth, we can still get high
yields, but we prevent the loss of that nitrogen into the atmosphere or into
the water system. That’s been the focus of a lot of the research that
we’ve done, and particularly the focus of the research in the Yaqui
Valley. In that environment, in the Yaqui Valley, the farmers apply a lot
of nitrogen, way more than normal amounts of nitrogen, 250-260 kg per hectare
of nitrogen, to their wheat crops. And they apply most of it about a month
before they plant, a month before they put the seeds in the ground. We expected
to see a lot of that nitrogen lost to the atmosphere. We expected to see high
emissions of ammonia, of nitric oxide, which is a greenhouse gas. But we also
expected to see a lot of it leaching out through the soil into water systems.
And we were concerned because, first of all, it was a lot of nitrogen being
applied, but also it was being applied not well timed to the demands of the
crop. In our studies we measured all of these things in the field and showed
that, indeed, very large losses of nitrogen were occurring, given the kind
of management practices that the farmers were using.

Interviewer: When was the first time you went to the Yaqui Valley
and why there?

PAM: Ros Naylor, one of my colleagues at Stanford, and I
knew that we wanted to work together on this issue of fertilizer in agriculture,
that we wanted to find those win/win situations where farmers could maintain
yields and profits but at the same time reduce the environmental cost of fertilization.
We had developed a plan of what we would like to do and we were invited to
come to the Yaqui Valley by Dr. Ivan Ortiz-Monasterio, the director general
of CMMYT, the international maize and wheat research institute, and an agronomist
in the Yaqui Valley, whose own research was focused on nutrient use by plants
and by agricultural plants. He visited the Yaqui Valley and thought he had
just the right place to carry out our plan. When we met Ivan, we knew that
we had the perfect match: that the three of us, an economist, an agronomist,
and a biogeochemist could work together on this issue, looking at how farmers
manage fertilizer, trying to understand why they do what they do, and looking
for alternatives that made sense for the farmers as well as the environment.
The Yaqui Valley provided the perfect place to do that.

Interviewer: What had been the traditional practice in the Yaqui
Valley?

PAM: The farmers in the Yaqui Valley were growing wheat,
irrigated wheat, and their typical practice was to apply a lot of nitrogen,
around 200 kilograms per hectare of nitrogen, in November or early December,
and then follow that with an irrigation of the dry soils, and then three or
four weeks later, they would plant their seeds. About a month after that,
they would add a little more water and a little more fertilizer. So altogether
they were applying about 250 kilograms per hectare of nitrogen. 75% of that
typically was applied about a month before the seeds were planted. When we
heard about that practice and when we saw that practice, we realized that
they were probably losing a lot of nitrogen before they ever even got the
seeds into the ground. And so, when we began doing our research there, we
asked, first of all, what were the farmers really doing, why were they doing
it that way, what were the logical and rational reasons that they decided
to manage fertilizer in that way, and what were the consequences of that management
practice, and then finally were there alternatives that would make sense for
the farmers and for their economic well being, as well as for the environment?

Interviewer: The farmers must have had the attitude, “Well,
we’ve been farming for years. We know how to do this. We’ve got
the best yields in the world.” What was working about that practice
that the farmers would decide to keep going with it even though it doesn’t
seem to make sense?

PAM: When wheat agriculture first started in the Yaqui Valley
back in the 1950s and 1960s, they had very low yields and farmers typically
were not applying very much fertilizer at all. Not even all of the land was
being fertilized, and where it was being fertilized, the levels of fertilization
were very, very low. That was a problem because they couldn’t optimize
the growth of the plant. They weren’t applying enough nitrogen to get
the best growth out of their crop. So the Mexican government started subsidizing
the application of fertilizer. They made fertilizer cheap on purpose so that
farmers could apply more. Over the years more and more farmers applied more
and more nitrogen because it was cheap and why not? It actually was very good
because it led to an increase in yields in the wheat in the valley. In the
1980s everybody was applying fertilizer and they were applying about enough—the
right amount of fertilizer to get the maximum yields. But for some reason,
they kept applying more and more and more. This is one of these interesting
cases where they overshot the need. They added more than they actually needed.
Partly it was because every once in a while they’d have a really great
crop-growing year because of the climate and they might get an exceptionally
good yield that year. In those years they probably needed that extra nitrogen.
Typically they wouldn’t have needed all that nitrogen, but they couldn’t
tell what the year was going to be like, they couldn’t tell which year
was going to be great and which year was going to be bad climatically, so
they just put a lot of nitrogen on, the more the better. I think also they
didn’t realize that they were losing a lot of nitrogen. They didn’t
have that information. One of the questions that we asked is why do they apply
so much of the nitrogen before they plant? It turns out that farmers all over
the world do that and they do it for pretty good reasons. The farmers in the
Yaqui Valley told us that they apply it a month before planting because it
helps them spread their labor. You know, they could take care of the fertilization
and then later on they could take care of the planting. They didn’t
have as much machinery, they didn’t have to have as many people working.
That’s one reason. Another reason is because they thought that the crop,
the wheat plants, really needed a lot of nitrogen right away, so they wanted
to make sure they had it on at the very beginning. And a third reason, and
maybe the most important reason, is that they were worried that if they didn’t
get it on early, they might not be able to get it on later when it starts
raining, or if it starts raining. They were trying to avoid risk by getting
it on very early and then not having to worry about it anymore. Of course
what they didn’t realize is that they were losing a lot of it; they
were basically pouring money down the drain by doing that.

Interviewer: How did you come up with a better scheme and then how
did you convince the farmers that they should try this?

PAM: In the first few years that we worked there as a team,
we spent a lot of time trying to understand what farmers were doing, why they
were doing it, and what the consequences were. We interviewed farmers, we
carried out farm surveys, we did many, many measurements of nitrogen processes
in the soil, and we truly learned what was going on in the valley. The next
step, then, was to say, “Well, what could they be doing instead?”
If we know that they’re losing a lot of nitrogen and that’s costing
them money, what are the alternatives they could try?” So we carried
out a number of experiments in farmers’ fields and also on the experiment
station there, the land on the experiment station. We compared what happens
under different kinds of fertilizer management, and we looked at how well
the crop grows, how much the wheat yield was, what the quality of the grain
was, what happened to the nitrogen in the soil, how much went off to the atmosphere,
how much was lost into water. And we did the economics of it, too. We tried
to figure out what the costs and benefits of different management practices
were. And we identified some very good practices that would reduce the amount
of nitrogen lost while still saving farmers a lot of money an maintaining
their yield and grain quality. In our best practice ,farmers would have applied
less nitrogen, but they would have applied more of it at planting, none of
it a month before planting. They would have had to add less nitrogen, but
it would have been more carefully timed to crop requirements. It seemed like
a great idea. It worked in most farmers’ fields, it worked in the experiment
station, and we talked with farmers about it. But they didn’t adopt
it. It seemed like a great idea, but they weren’t going to do it.

In phase two of the research we tried to figure out why they wouldn’t,
why they couldn’t adopt it. What was the problem for them? In that research
we found that there’s actually a lot of variability out there year to
year. Some years the climate’s perfect for growing wheat, some years
it’s terrible, some years it’s in between. We also realized that
not all of the land there is the same. There’s a lot of variation in
soils in that valley. It looks all the same, but it’s quite different.
And finally, we realized that different farmers do different things. Some
farmers are absolutely great managers and some aren’t quite so good
in terms of managing fertilizers. Variability was a huge part of their life.
Our one best practice just wasn’t going to be good for everybody under
every condition and they weren’t adopting it. But the other thing that
we discovered in our research is that one of the reasons they weren’t
trying the new practice is that their credit unions were telling them not
to. The credit unions in the Yaqui Valley are kind of like farmer associations.
They do provide credits, that is they loan money to the farmers, but they
also give them advice, give them access to markets, get good fertilizer deals
for them, and seed deals and so forth. So it’s a very important part
of the farmers’ lives. And those credit unions were risk-averse, too.
They weren’t ready for the farmers to completely change their fertilizer
management practice, even if it seemed like it was a good idea in many places
under many environmental conditions. When we realized that, when we understood,
first of all, the importance of variability and risk aversion because of variability,
and we also understood the importance of the credit unions and the decisions,
we changed our research strategies. Then Ivan Ortiz-Monasterio began a new
set of research to look for real-time measures of nitrogen availability in
the fields so that farmers would know what it’s like today, this year,
under these conditions, on this field, and they could decide how much fertilizer
to apply based on that knowledge.

Interviewer: Can you talk about the hand-held radiometers and how
this great breakthrough came about?

PAM: When we realized the issue of variability and the need
to have more information on a real-time basis, Ivan Ortiz-Monasterio began
collaborating with others who had been developing a hand-held radiometer,
an instrument that would allow measurement of the nitrogen content of the
leaves of the plant—something that you can walk out into the field with
and learn something about the nutritional level of the plants right then and
there. He developed a management strategy that would allow him to compare
the nitrogen content of a fertilized strip of land compared to an unfertilized
field. When the radiometer’s information indicated that the plants really
needed nitrogen or they wouldn’t grow to their maximum, then it was
time to apply the nitrogen. It allowed farmers real-time information and on
a site-by-site basis. When the radiometer’s data suggested it was time
to fertilize, then they’d bring the fertilizer in and apply it as needed.
The interesting thing there is that the credit unions became interested. We
actually tried to get them to be interested in the process. Ivan invited them
to become part of the research. They were interested in that because they’re
always looking for ways to save money. Ultimately, when they saw that the
hand-held radiometer approach works and that it could save their farmers a
lot of fertilizer and thus save them a lot of money, they decided to invest
in them for their members. So the credit unions themselves bought the hand-held
radiometers for all of their members to use, and they bought it because it
was a money savings device.

Interviewer: You’ve mentioned the importance of the work of
Mike Beman, a member of your team. Can you tell us a more about that.

PAM: When we were evaluating what happens to nitrogen in
the farmers’ fields, we found that quite a bit of it, maybe 20-50 kilograms
per hectare of nitrogen, actually leaches out of the farmers’ fields
and moves into the groundwater or the surface-water systems. Those systems
lead right out to the Sea of Cortez, to one of the world’s biodiversity
hot spots. We were very interested in what that meant to the ecosystems of
the marine system of the Sea of Cortez. So Mike Beman, a graduate student
who worked as part of our team, began a study to evaluate the consequences
of all of that nitrogen and other stuff moving from land to the ocean on the
processes going on in the Sea of Cortez. Mike used a couple of different approaches,
including sea-based measurements of what’s going on in the water itself,
as well as remote sensing studies in which he used satellite data to look
at chlorophyll blooms, at these phytoplankton blooms, and to try to relate
those blooms of algae in the water to what’s going on on the land. Mike’s
results were absolutely amazing, surprising. First time ever that anyone was
able to use very high temporal resolution, that is, very high time frequency
of sampling from satellites to look at phytoplankton blooms in the water.
And because he could do that so well, because he could have so much day-to-day
information about phytoplankton blooms, he was able to relate those blooms
of algae to fertilizer and irrigation events on land. What he was seeing was
that fertilizer on land makes its way through the water systems into the ocean
and very often leads to very high phytoplankton blooms that then go on to
affect the whole Sea of Cortez.

Interviewer: What happened when he showed the data to the farmers?

PAM: The results of Mike’s research made its way back
to the farmers. Ivan Ortiz-Monasterio and Mike Beman both spoke with farmers
about it and the farmers, I think, were surprised, impressed, and concerned
that their actions on land, their management on land, was actually able to
have an effect far away, off of their fields. Most people don’t have
that kind of information, so they don’t understand what the issues are.
Those results, I think, got a lot of people’s attention. The farmers
could see their money going down the drain, and moreover, they could see it
heading out to the ocean as well.

Interviewer: How quickly did the nitrogen cause the blooms?

PAM: Very quickly, actually. Mike used another one of the satellite sensors
to measure sea-surface temperature and he used that information to tell him
when there was upwelling of nutrients, because the up welled water is very
cold water. He could tell when the cold waters were at the surface of the
ocean there; any phytoplankton blooms that were going on when there was cold
water was probably because of the nutrients being up welled. So he separated
those out and got rid of those from his data set and just looked at the rest
of the algal blooms. He could time those within a week to the fertilizer irrigation
events that were going on on land. In less than a week after most of the farmers
fertilized, he could see the results in the ocean. Of course the key here
in the Yaqui Valley is that most farmers do things at exactly the same time,
so it’s very synchronous irrigation fertilization. All happens over
a week- to two-week period. And Mike Beman was able to see the reflection
of that in the blooms of algae in the Sea of Cortez.

Interviewer: Obviously Yaqui is just one small place, but are you
somehow using this to apply to other places?

PAM: We selected the Yaqui Valley as a study site in part
because it is so representative of so much of the wheat-growing area in the
developing world. It’s agro-climatically representative of about 40%
of the wheat-growing area so what we learned in that place is relevant to
other places. We also selected the valley because it is the home of CIMMYT,
the International Maize and Wheat Research Institute. Researchers from all
over the world come to CIMMYT to learn new methods, and CIMMYT’s researchers
go out to other parts of the world with their new technologies. So we knew
that we had an automatic way to influence what was going on in other parts
of the world. Another reason that we worked in the Yaqui Valley is that it
was small enough to really get our hands around, and yet what we could learn
there was relevant in a lot of other places. The tools that we developed,
including the mathematical models that we developed, things like the hand-held
radiometer or new fertilizer management practices, are all things that can
be extended to many other parts of the world. Finally, the Yaqui Valley is
also a case study, in a sense, of how interdisciplinary teams can work together
on sustainability issues for sustainable agriculture. People around the world
now recognize the Yaqui Valley as an example of how ecologists and agronomists
and economists and farmers and credit union advisors and others can work together
to develop new approaches that make sense for people and for the environment.

Interviewer: What’s the role of the farmer in all of this?

PAM: The farmer, of course, is the ultimate decision maker.
If there’s one thing we’ve learned in this work, it’s that
we have to be in constant contact and interaction with decision makers in
order to make sure that our research is actually useful and usable and, in
the end, used by them. It has led me to believe that if university research
teams like ours, or any research team, wants to be effective, wants to have
what they learn be actually used by someone, it’s probably very smart
to partner with the decision makers, in this case with the farmers.

Interviewer: What excites you about this work?

PAM: I love the opportunity to learn new things about how
the world works. I’m a researcher and I love that sense of discovery,
and we did learn some brand new things in this project. But I think more importantly
for me, it’s having the feeling that what we are doing will actually
help somebody; it will help people but it will also help the environment.
That sense of making sure that while we’re contributing to new knowledge,
we’re also contributing to problem solving is very important for me.

Interviewer: In our final program in the series we’re trying
to wrap up the entire course by giving a hopeful ending. Do you think human
beings have the capacity to be able to share the earth’s bounty and
have quality of life for everybody?

PAM: Sometimes when you realize all the unmet needs of people
worldwide, the fact that there are people who go to bed hungry every night,
millions and billions of people who don’t have access to clean water
and to modern energy and to education and employment, you can get very, very
depressed. And when you think about all the environmental problems that we’re
facing: change in the atmosphere, climate change, land-use changes, loss of
biological diversity, you can get even more depressed. But you know, I’m
an optimist. I see great progress. I see great movement toward a transition
to sustainability. I think if you look at corporations, governments, individuals,
so many people are taking actions now to balance the need, to meet the needs
of people and the environment. There’s so much good news out there.
The key is that we’re going to have to move a lot faster, we’re
going to have to push this transition to sustainability ahead much, much more
quickly. But the bottom line is we’ve already taken the first couple
of steps and we’re moving in the right direction.

Interviewer: Is there an historical precedent for problems of similar
size that have been managed somehow?

PAM: I’m thinking about Jarred Diamond’s book
Collapse. He talks about communities of people that made it and communities
that didn’t. I think one of the messages that comes from his writing
is that if people act, if they recognize that there are multiple and interacting
challenges that they’re faced with and they act, they can survive. And
I think there are examples of that in our ancient history. In modern history,
yes, there are still some examples. Fifty years ago, human population was
growing incredibly rapidly and we didn’t have the food to feed them.
The green revolution, for all of its challenges, was dramatically successful
in that we’ve been able to keep food production at pace with human population
growth. Yes, there are still people who go hungry, but it’s not because
of lack of food. It’s because of lack of access to the food that’s
there. It was a tremendous success. And it was a success that’s thanks
in part to the global community coming together and saying we need to work
hard on this. The irony is that some of the challenges that we’re facing
now are a result of that success, and we just need to go forward, identify,
and use new approaches for agriculture that continue that success in terms
of feeding people but at the same time reduce the environmental consequences
that will influence the ability of our children to have their needs met.